Growth, acidification and proteolysis performance of two co-cultures (Lactobacillus plantarum-Bifidobacterium longum and Streptococcus thermophilus-Bifidobacterium longum)

• Published in: African journal of biotechnology Vol. 9; no. 10; pp. 1463 - 1469
• Main Authors: K, Belkaaloul, A, Chekroun, A, Ait Abdessalam, D, Saidi, Kheroua, O
• Format: Journal Article
• Language: English
• Published: 08.03.2010
• Subjects: Acidification; Bifidobacterium longum; Colony-forming cells; Fermentation; Kinetics; Lactic acid; Lactobacillus; Lactobacillus plantarum; lactoferrin; Milk; Mixed culture; pH effects; Proteolysis; Streptococcus
• ISSN: 1684-5315; 1684-5315
• DOI: 10.5897/AJB09.1090

In this study, the fermentation and proteolysis of two co-cultures were investigated. Two fermented cow skim-milk lactoferrin 1 (LF1) and lactoferrin 2 (LF2) were prepared. LF1 was inoculated with Bifidobacterium longum (Bf I) and Streptococcus thermophillus (St I) while LF2 was inoculated with Lactobacillus plantarum (Lb O) and B. longum (Bf I). Incubation was at 42C for 8 h. The enumeration revealed bacterial growth in all fermented milk. Maximum growth of (Lb O) and (Bf I) was observed when mixed together after 2 h of fermentation in comparison with Bf I and St I with values of 10 super(9) and 3.10 super(8) cfu/ml, respectively. The kinetics of acidification (pH and lactic acid production) gave significant values (p < 0.01) for LF2 when compared to LF1 and sterile milk (LS). The proteolytic activity (functions a-NH sub(2) released in kM/mg) and total proteins (in kg/mg) gave significant values (p < 0.05) for LF2 when compared to LF1. Two mixed cultures (Lb O- Bf I) and (St I-Bf I) showed proteolysis of ss-lactoglobulin (ss-Lg) and a-lactalbumin (a-la).